KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q245646: DNS Stops Responding to UDP Name Queries

Article: Q245646
Product(s): Microsoft Windows NT
Version(s): winnt:4.0
Operating System(s): 
Keyword(s): kbWinNT400PreSP7Fix
Last Modified: 08-MAY-2002

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Windows NT Server version 4.0 
- Microsoft Windows NT Server, Enterprise Edition version 4.0 
-------------------------------------------------------------------------------

SYMPTOMS
========

The DNS server may become silent and stop responding to name queries over User
Datagram Protocol (UDP). If you restart the DNS service, the problem is
resolved.

CAUSE
=====

The DNS service runs with two UDP listener threads per processor in the server.
Certain DNS queries expose a problem in a listener thread which causes the query
to stop and never restart. Eventually all the UDP listener threads get into this
state, after which point no more name queries can be processed by the DNS
server.

RESOLUTION
==========

A supported fix is now available from Microsoft, but it is only intended to
correct the problem described in this article and should be applied only to
systems experiencing this specific problem.

To resolve this problem, contact Microsoft Product Support Services to obtain the
fix. For a complete list of Microsoft Product Support Services phone numbers and
information on support costs, please go to the following address on the World
Wide Web:

  http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

NOTE: In special cases, charges that are normally incurred for support calls may
be canceled, if a Microsoft Support Professional determines that a specific
update will resolve your problem. Normal support costs will apply to additional
support questions and issues that do not qualify for the specific update in
question.

The English-language version of this fix should have the following file
attributes or later:

  Date        Time    Size      File name   Platform
  --------------------------------------------------
  11/05/1999  21:42   178,448   Dns.exe     Intel
  11/05/1999  21:41   299,280   Dns.exe     Alpha



STATUS
======

Microsoft has confirmed this to be a problem in Windows NT 4.0.

MORE INFORMATION
================

The listener threads actually cause an exception because of an uninitialized
pointer. However, all the threads are wrapped in an exception handler which
means that the offending thread is silently stopped, rather than affecting the
entire server. As part of the fix to this problem, an event is now generated to
indicate that an exception has occurred on a thread and that it has stopped.

Additional query words:

======================================================================
Keywords          : kbWinNT400PreSP7Fix 
Technology        : kbWinNTsearch kbWinNT400search kbWinNTSsearch kbWinNTSEntSearch kbWinNTSEnt400 kbWinNTS400search kbWinNTS400
Version           : winnt:4.0
Hardware          : ALPHA x86
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.